A path through a weighted finite-state transducer (WFST) [1]} maps an input sequence to an output sequence, where each transduction, called arcs, has an associated weight w, see Figure REF . A path's weight W is the sum of all its arcs' weights, and a deterministic WFST outputs a single shortest path which has the minimum weight.
As a starting point for our proposed system we use a deterministic WFST based on the NeMo text normalization framework [2]}, which does not take context into account (hereafter DetWFST). In case of ambiguous inputs such as “1/4" in “The trains leaves on 1/4", a deterministic WFST can mistakenly choose “one quarter" over “January fourth".
